Forever Together's superb four and a half length victory was a seventh in the fillies' mile and a half Classic for trainer Aidan O'Brien.

Ridden by O'Brien's son Donnacha, who won the 2000 Guineas at Newmarket aboard Investec Derby favourite Saxon Warrior last month, Forever Together was sent off at odds of 7/1. Wild Illusion, the 5/2 favourite, finished second.

Aidan O'Brien first won the £500,000 Group One with Shahtoush in 1998. Since then, Imagine (2001), Alexandrova (2006), Was (2012), Qualify (2015) and Minding (2016) have been added to the roll of honour.

Forever Together is a daughter of Galileo out of the Theatrical mare Green Room, also dam of Group One winner Lord Shanakill. She is the first maiden to win the Investec Oaks since Sun Princess in 1983.

O'Brien said: " This is incredible. I am so delighted for everyone; Padraig who looks after her, Emmet who rides her, then John [Magnier], Michael [Tabor], Derrick [Smith], Sue, Gay and Doreen. It is brilliant for everyone.

"Forever Together is a staying filly who gets the trip very well and is obviously by Galileo, which is a massive advantage.

"Donnacha gave her an unbelievable ride. I am over the moon.

"It went according enough to plan. We weren't sure about the ground - who would act on it and who wouldn't. Donnacha rides her in all her work and he was very happy with her after Chester [she finished second in the Cheshire Oaks]. She was still a maiden until today, but the ground was so bad [in Ireland this spring] we couldn't stand it, so we skipped the maidens and she ran a lovely race at Chester.

"I think we will go to the Irish Oaks now. Obviously we will have to see what the lads want to do, but you'd be thinking she'd love the Curragh. We're very happy with all the fillies, really.

"We're delighted and so grateful to a lot of people that we are in this position and we don't take that for granted for one minute. Donnacha is a very good rider - he's very cool and confident. He's been watching races since the day his eyes opened so tactically he's

William Buick, on the 5/2 favourite and second placed Wild Illusion, said: "She ran well, stayed and handled the ground. They will all prefer good ground but she handled that ground well. I thought the filly that won the race (Forever Together) has improved a lot from Chester and just put the race to bed."

Wayne Lordan, on 8/1 chance and third Bye Bye Baby, said: "She bowled away. She likes to bowl away and I was happy for her to do so. But she just wasn't good enough on the day."

Ryan Moore, on fourth Magic Wand (4/1), said: "She ran a very good race, but she didn't enjoy the ground."

Padraig Beggy, on fifth home Flattering (11/1), said: "I ran a good race. The ground is getting a little bit shifty now and when we came to the straight she changed her legs a couple of times. She stayed on well to the line."

James Doyle, on sixth Give And Take (16/1), said: "It was just a bit disappointing. We had hoped she would run a bit better than that. She never really got into a rhythm."

Adam Kirby, on seventh Perfect Clarity (5/1), said: "The race went very smoothly and was very cleanly run. There are no excuses but unfortunately she hated the ground. She came with a live chance but just faltered on the ground. She is still a very good filly and there is still a lot of fun to be had with her."

Seamie Heffernan, eighth on I Can Fly (9/1), said: "I ran terrible."

Jamie Spencer, on ninth Ejtyah (25/1), said: "The ground was against her."